Impact de l’accumulation en certains métaux lourds (cuivre, zinc et plomb) dans les amarantes irriguées de la ville de Bujumbura
Date
2025-08
Journal Title
Journal ISSN
Volume Title
Publisher
UB, EANSI
Abstract
Heavy metals, such as mercury, chromium, cadmium, arsenic, and lead, are toxic elements that accumulate in the food chain, harming living organisms even at low concentrations. In the city of Bujumbura, the use of wastewater to irrigate amaranth plots leads to contamination, which can cause illness among consumers. The overall objective of this study is to assess heavy metal contamination in amaranth cultivated in Bujumbura, by analyzing the concentration levels of these contaminants. The study was conducted in four areas of Bujumbura City Hall such as Buterere, Buyenzi, Musaga where amaranth farmers use wastewater for irrigation, and a control site at the Mutanga campus using tap water. The heavy metals analyzed include Cu, Pb, Zn, and Cd. This study highlights the impact of irrigation water on crop contamination. Data collection began with the preparation of control fields in the MUTANGA campus greenhouse, followed by the collection of amaranth leaves in the four study areas, including the control site. Samples of 500 g of amaranth leaves were collected in triplicate. Mineral element analysis was performed using flame atomic absorption spectrophotometry at ISABU, and data analysis was carried out using SPSS version 20 software. Physicochemical analysis shows that heavy metal levels vary depending on the growing site and the quality of the irrigation water used. The levels ranged from Mutanga to Cu=4.55 mg/kg, Pb=9.83 mg/kg, Zn=38.96 mg/kg, and Cd≤0.1 mg/kg, respectively, for Cu, Pb, Zn, and Cd in the control samples; 7.42mg/kg, Pb=11.66mg/kg, Zn=67.68mg/kg, Cd≤0.1mg/kg respectively for Cu,Pb, Zn and Cd for samples from Buyenzi; 5.60mg/kg, Pb=11.42mg/kg, Zn=80.91mg/kg respectively for Cu, Pb, Zn and Cd for samples from Buterere and Cd≤0.1mg/kg and Cu=6.75mg/kg, Pb=14.42mg/kg, Zn=61.00mg/kg and Cd≤0.1mg/kg respectively for Cu, Pb, Zn and Cd for samples from Musaga. These results highlight the impact of irrigation water on heavy metal contamination. The sampling sites exhibited higher levels of heavy metal contamination
compared to the MUTANGA control site, due to the quality of the irrigation water.
Description
Mémoire présenté et défendu publiquement en vue d’obtention d’un Diplôme de Master en Sciences des Aliments et Nutrition Spécialité : Technologie et Qualité des Aliments